The invention relates to a Q-switched laser system of the type which includes a laser-active medium in a resonator construction, an arrangement for optical pumping, and a passive Q-switch.
Solid-body laser systems for laser lithotripsy are known from the publications WO 90/12544, WO 90/04358, WO 91/05332 and AT-B-380634. In these systems, which operate with short, single pulses, the fiber which transmits the energy to the location of application is destroyed very quickly in practical use because of the short pulse lengths used in the systems. Moreover, the technical structures of these laser systems are very cost- and maintenance-intensive.
In addition, experimental investigations have revealed that it is favorable to operate with a so-called double pulse in laser lithotripsy, which involves the transmission in rapid succession of two pulses to the location of application, with the one pulse being shifted toward the actual energy-carrying pulse toward the short-wave range ("blue") typically representing the harmonic of the carrier wave length. This combination permits premature ignition of the optical breakdown (plasma) at the rock surface to be broken up, and thus allows for a greater effectiveness in rock breaking. However, the disadvantage associated herewith is rapid fiber burnup in practical use.